Such reamers are known from CN102059399A, for example. These reamers have, for example, a free end at the front facing the workpiece, said end having a separate head that carries the cutting edges and can be made of a harder material than the basic tool body material. Furthermore, there are reamers that have a plurality of separate cutting inserts at a distance from the front end on their circumferential section, said cutting inserts each being plate-like and inserted into longitudinal slots that essentially run along the length of the basic tool body.
Various cutting materials, including, for example, hard metals, are used for the cutting edges. Moreover, theoretically polycrystalline diamond is an advantageous cutting material. However, this has the considerable disadvantage that high operating temperatures can result in graphitization. This occurs particularly in the machining of ferrous materials.